Study on mechanical parameters of disturbed sand layer in caisson foundation of Shanghai-Nantong Yangtze river bridge

摘要

The caisson foundation of the No.29 main pier of Shanghai-Nantong Yangtze River Bridge has a large range of sand gushing,not only the foundation of the caisson is inclined,but also the sand layer of the base of the caisson and the side wall of the caisson has been greatly disturbed.The bearing capacity of basement soil is reduced,and the compressive modulus of soil is reduced obviously.How to determine the extent of the disturbance,the degree of disturbance and the mechanical parameters of the disturbed soil layer is the key to how to control the subsequent construction deformation.The relationship between the compression modulus and the compression modulus is established by numerical simulation of the lateral loading test process,and the mechanical parameters of the disturbed sand layer are determined.It provides reasonable and reliable calculation parameters for analyzing the attitude change of the No.29 main pier under the construction load in the later stage.